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Pragmatic Stats: Median

What is it?

The median is the middle point of a sample or population of scores. To break it down one step
further, if we have an odd number of samples and we sort them, the median is
the sample in the center. In the case we have an even number of samples, the median
would be the average of the two middle samples.

Symbols & Formulas

Formula - Sort samples, select sample in middle position (if odd number of samples).
Otherwise take the mid-point between the two samples in the center.

When Should I Use This?

Use:

It should be used to ‘get a sense of your data’ in conjuction with the mean
and standard deviation.

Don’t Use:

Not sure there is a blanket time not to use it (at least in the case of
exploratory analysis). But there are some things you should know (see next section).

Assumptions, Prerequisites, and Pitfalls

The median is great for giving us an idea of what our data looks like….. but it
does not tell the whole story. This is exactly why we have other measures
of centrality like mean and measures of variation such as standard deviation and variance.